Activity Of Nanozymes Research Articles

Probing the Active Nitrogen Species in Nitrogen-Doped Carbon Nanozymes for Enhanced Oxidase-Like Activity.

Nitrogen doping emerges as a potent approach to enhance the oxidase-like activity of carbon nanozymes. However, the unclear knowledge of the active nitrogen species within nitrogen-doped carbon nanozymes hinders the advancement of high-performance carbon nanozymes. Herein, a group of nitrogen-doped carbon (N/C) nanozymes with controllable nitrogen dopants are successfully synthesized via a dicyandiamide-assisted pyrolysis method. The intrinsic connection between different nitrogen configurations (pyridinic N, pyrrolic N, and graphitic N) in N/C nanozymes and the oxidase-like performance are experimentally investigated. The results confirm pyridinic N is the active nitrogen species in N/C nanozymes for enhanced oxidase-like activity. Theoretical calculations further reveal the potential regulatory mechanism is pyridinic N can increase the local charge density of neighboring carbon atoms and accelerate the adsorption and activation of molecular oxygen. Notably, the optimized N/C nanozyme with the highest pyridinic N ratio presents impressive oxidase-like performance, surpassing most of the previously reported oxidase-like materials. Moreover, the optimized N/C nanozyme exhibits excellent antibacterial properties and can be easily incorporated into common medical and hygiene products to give them spontaneous antibacterial properties. The work will facilitate the rational design of carbon nanozymes with high-performance oxidase-like activity for applications in the antibacterial field.

Targeted Enrichment of Nucleic Acid Bionic Arms Enhances the Hydrolysis Activity of Nanozymes for Degradation and Real-Time Monitoring of Organophosphorus Pesticides in Water.

Organophosphorus pesticides (OPs) pose significant environmental and health risks, and their detoxification through catalytic hydrolysis using zirconium-based metal-organic frameworks (Zr-MOFs) has attracted considerable interest due to the strong Lewis acid metal ions. Albeit important, the defects of the materials for OP hydrolysis (e.g., poor degradation efficiency, rate, and selectivity) limit their further application. Herein, a nucleic acid bionic arm-modified biomimetic nanozyme (MOF-808-Apt) was designed through a Zr-MOF and a specific aptamer against OPs, which was employed for the efficient and selective degradation of OPs. At the system, the functionalized biomimetic nanozyme can continuously capture trace OPs onto its catalytic sites for degradation with the fabricated nucleic acid bionic arms, significantly improving their catalytic activities compared to bare MOF-808 using paraoxon as a model of OPs, providing better performances including (i) an excellent degradation efficiency, boosting from 4 to over 60% within 6 min; (ii) a satisfactory catalytic rate (the pseudo-first-order rate constants of paraoxon hydrolysis improved from 0.09 to 0.14 min-1); and (iii) good selective degradation because of aptamers used. Besides, this dynamic degradation process could be visually recorded in real time with high sensitivity (limit of detection, 0.18 μM) because of the obvious color change of the reaction solution and signal amplification ascribed to increasing local concentrations of targets by the nucleic acid bionic arms. Summarily, this work provides a new strategy for the effective and selective degradation of typical OPs and concurrent monitoring of their dynamic degradation process.

Multifunctional porphyrinic metal-organic framework-based nanoplatform regulating reactive oxygen species achieves efficient imaging-guided cascaded nanocatalytic therapy.

The integration of reactive oxygen species (ROS) related photodynamic therapy (PDT) with the strategy of reshaping the tumor microenvironment (TME) has emerged as a potential approach for nanodiagnostic and therapeutic interventions. However, the therapeutic efficacy based on ROS treatments may be hindered by intracellular antioxidants such as glutathione (GSH) and tumor hypoxia. To address these challenges, a nanoplatform based on GSH-responsive multifunctional porphyrinic metal-organic framework (PCN-224@Au@MnO2@HA, PAMH) was proposed. It was developed through a layer-by-layer in-situ growth method. This method avoids the need for high-temperature calcination and complex modification processes while improving the stability of PCN-224 in a phosphate-rich environment. GSH depletion leads to oxidation-reduction imbalance in TME. With the inactivation of GSH peroxidase 4 (GPX4), the content of hydrogen peroxide (H2O2) increases, ultimately triggering lipid peroxidation (LPO) and promoting ferroptosis. The catalase-like activity of Au nanozymes facilitates the generation of oxygen (O2), thereby mitigating tumor hypoxia and downregulating hypoxia-inducing factors (HIF-1α). Due to the presence of porphyrin ligands in PCN-224, the generated O2 can be further converted to toxic singlet oxygen (1O2) under laser irradiation. Additionally, the platform allows near-infrared (NIR) fluorescence imaging, providing real-time information on intracellular GSH changes during PDT and ferroptosis. The PAMH nanoplatform has shown effective inhibition of tumor growth in subcutaneous models via both intravenous and intratumoral injection, indicating its potential in modulating reactive oxygen/sulfur species and reshaping TME, thereby facilitating imaging-guided cascaded nanocatalytic therapy.

Cu-curcumin nanozyme for detection of Cr(VI) through an off-on strategy based on peroxidase mimicking activity.

Hexavalent chromium ions (Cr(VI)) possess inherent toxicity and propensity for bioaccumulation in the environment. Herein, a Cu-curcumin nanozyme was synthesized via a one-pot solvothermal method. Based on the high peroxidase-like activity of the Cu-curcumin nanozyme, a novel and economical colorimetric platform has been developed for Cr(VI) assay. In the presence of hydrogen peroxide (H2O2), the Cu-curcumin nanozyme can catalyze the transformation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) into the blue product oxTMB. 8-Hydroxyquinoline (8-HQ) can inhibit the catalysis of the Cu-curcumin/TMB/H2O2 system, causing the blue color to fade. With the addition of Cr(VI), the peroxidase-like activity of the Cu-curcumin nanozyme is increased significantly, leading to the restoration of the Cu-curcumin/TMB/H2O2 system color. After optimization of the experimental parameters, a novel colorimetric sensor for Cr(VI) assay has been successfully developed with a low limit of detection (LOD) of 31.5 nM, affirming its potential for accurate Cr(VI) quantification in environmental specimens. In addition, paper strips integrated with a smartphone platform enhance the versatility and portability of the Cr(VI) assay, achieving an LOD of 0.1 μM.

Triethylamine regulated MOFs-derived peroxidase-like nanozymes for colorimetric analysis of glyphosate with boosted catalytic activity

Developing accurate and rapid methods for analyzing organophosphorus pesticides is essential to ensure water quality and food safety due to their significant chemical and biological toxicity. This study presents a novel colorimetric sensor for glyphosate based on inhibiting Fe/ZnO nanozyme activity. By doping with iron and modulating the growth process of Fe/Zn MOFs precursors with triethylamine (TEA), Fe/ZnO nanozymes with substantial active surfaces and abundant Fe active sites were derived. The Fe/ZnO possessed excellent peroxidase-like activities, measuring 15.3 and 7.5 times higher than those of the materials synthesized without iron doping (ZnO) and the use of TEA (Fe/ZnO-w), respectively. Glyphosate inhibited the enzyme-like activity of Fe/ZnO by adsorbing on its surface through electrostatic interaction and occupying its catalytic active site. Based on this mechanism, a colorimetric sensing assay was created to directly and selectively detect glyphosate. The linear range for glyphosate detection was 0.02 to 10 mg L−1, with a detection limit (3σ) of 15.6 μg L−1. The proposed method has been successfully applied to the analysis of real samples. Metal oxides derived from well-designed MOFs provide a simple and effective strategy for creating high-performing pesticide detection platforms.

The smartphone-assisted sensing platform based on manganese dioxide nanozymes for the specific detection and degradation of hydroquinone.

Hydroquinone (HQ) is a prevalent pollutant in aquatic environments, posing significant risks to ecosystems and human health. Practical methods for the simultaneous detection and degradation of HQ are essential. To address this requirement, a dual-mode detection and degradation strategy has been developed utilizing designed nanozymes (DM) consisting of a porous SiO2 core and MnO2 shell. Due to the catalytic activity of DM nanozymes, the three types of reactive oxygen species (ROS), singlet oxygen (1O2), superoxide anion (O2•-), and hydroxyl radical (•OH), were generated to induce the color transferring of 3,3',5,5'-tetramethylbenzidine (TMB) from colorless to blue form (oxTMB). During the reductive HQ-mediated oxTMB fading, the DM has significant selectivity towards HQ from isomers (catechol and resorcinol) due to the differing reductive reaction rates, with an excellent linear range of 0.2-45 μM with a detection limit as low as 0.11 μM. In addition, according to the color parameter changes in the sensing process, colorimeters and smartphones are utilized to achieve on-site and convenient HQ detection. Besides, the DM nanozyme can oxidatively decompose HQ without auxiliary equipment. We believe this research provides a powerful tool for detecting and removing HQ precisely.

Co-catalytic enhancement of peroxidase-like activity of Fe-MOFs nanozymes by AuNPs for efficient specific detection of Hg2+

Co-catalytic enhancement of peroxidase-like activity of Fe-MOFs nanozymes by AuNPs for efficient specific detection of Hg2+

A colorimetric strategy and smartphone-based test strip for the detection of glucose based on the peroxidase activity of a hemin-derived nanozyme.

Nanozymes are nanomaterials with catalytic properties similar to enzymes and offer advantages over natural enzymes such as lower cost, ease of storage, and convenience for large-scale preparation. Thus, they have received increasing attention and are extensively applied in fields such as chemistry, sensing, food, environment, and medicine. Herein, a hemin-derived nanozyme (Hemin-CDs) was prepared using hemin as the precursor and used to substitute the natural horseradish peroxidase (HRP) for colorimetric detection. The prepared Hemin-CDs exhibit excellent water dispersibility, stability and superior peroxidase-like activity. They catalyze the oxidative coupling of colorless 4-aminoantipyrine (4-AAP) with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline sodium salt (TOOS) in the presence of H2O2, forming a purple quinone diimine dye with an absorption peak at 554 nm, which enables the quantification of H2O2 by measuring the absorbance. Quantitative detection of glucose was further demonstrated under physiological conditions. The detection of H2O2 and glucose takes only 10 minutes, with linear ranges of 1-150 μM and 2.5-300 μM, and LODs of 0.867 μM and 1.026 μM, respectively. Glucose in human serum was successfully detected with satisfactory recoveries (87.5-104.0%). Furthermore, a test strip was developed, and a smartphone was utilized to recognize the color of the test position, enabling rapid and accurate quantification of glucose concentrations within 5 minutes, which promises to enhance the accessibility and convenience of glucose testing.

Nanomineralzyme as a novel sustainable class of nanozyme: Chalcopyrite-based nanozyme for the visual detection of total antioxidant capacity in citrus fruit.

Chemically-synthesized Nanozymes that are widely used as alternatives to enzymes face challenges such as high precursor costs, complex preparation processes, and limited catalytic efficiency. To overcome these drawbacks, we introduce naturally derived nanozymes, nanomineralzymes, as a promising alternative, offering benefits like affordability, cost-effectiveness, and scalability. Chalcopyrite (CP, CuFeS2) was sourced from a mineral deposit, and CP nanoparticles were produced by milling. These nanoparticles exhibited strong peroxidase-like activity, achieving a low Michaelis-Menten constant using 3,3',5,5'-tetramethylbenzidine as a substrate. Characterizations revealed the presence of cuprous, cupric, ferrous, and ferric ions in the CP mineral. The proposed mechanism involves an enhanced Fenton and Fenton-like process due to the metal ions' multi-valence states. CP nanozyme activity was inhibited to produce radicals due to hydrogen atom transfer and single electron transfer with ascorbic acid, glutathione and cysteine. The CP mineralzyme-based total antioxidant capacity probe was successfully used for detection of TAC in citrus fruits.

Peroxidase (POD) Mimicking Activity of Different Types of Poly(ethyleneimine)-Mediated Prussian Blue Nanoparticles.

Prussian blue nanoparticles (PBNPs) have been identified as a promising candidate for biomimetic peroxidase (POD)-like activity, specifically due to the metal centres (Fe3+/Fe2+) of Prussian blue (PB), which have the potential to function as catalytically active centres. The decoration of PBNPs with desired functional polymers (such as amino- or carboxylate-based) primarily facilitates the subsequent linkage of biomolecules to the nanoparticles for their use in biosensor applications. Thus, the elucidation of the catalytic POD mimicry of these systems is of significant scientific interest but has not been investigated in depth yet. In this report, we studied a series of poly(ethyleneimine) (PEI)-mediated PBNPs (PB/PEI NPs) prepared using various synthesis protocols. The resulting range of particles with varying size (~19-92 nm) and shape combinations were characterised in order to gain insights into their physicochemical properties. The POD-like nanozyme activity of these nanoparticles was then investigated by utilising a 3,3',5,5'-tetramethylbenzidine (TMB)/H2O2 system, with the catalytic performance of the natural enzyme horseradish peroxidase (HRP) serving as a point of comparison. It was shown that most PB/PEI NPs displayed higher catalytic activity than the PBNPs, with higher activity observed in particles of smaller size, higher Fe content, and higher Fe2+/Fe3+ ratio. Furthermore, the nanoparticles demonstrated enhanced chemical stability in the presence of acid, sodium azide, or high concentrations of H2O2 when compared to HRP, confirming the viability of PB/PEI NPs as a promising nanozymatic material. This study disseminates fundamental knowledge on PB/PEI NPs and their POD-like activities, which will facilitate the selection of an appropriate particle type for future biosensor applications.

High-Spin States of Manganese(III) Enable Robust Cold-Adapted Activity of MnO2 Nanozymes.

Developing novel cold-adapted nanozymes and elucidating their mechanisms of action remains a great challenge. Inspired by natural oxidases that utilize high-spin and high-valent metal-oxygen intermediates to achieve high efficiency at low temperatures, in this study, a series of MnOx nanomaterials with varied valence and spin states are synthesized. The activity assay revealed that the oxygen vacancy-engineered ε-MnO2 nanozyme displayed excellent cold-adapted oxidase-like properties, and no observable activity loss is observed in the temperature range of -20 to 45 °C. The superior performance is attributed to the high-spin Mn(III)-O species coupled with its induced Jahn-Teller effect, which facilitates the dissociation and activation of oxygen at low temperatures. As a proof of concept, an excellent cold-adapted δ-MnO2 nanozyme can be obtained using Mn3O4 as the precursor by regulating the spin state of Mn(III). Moreover, a novel and effective degradation strategy for corn stalk at low temperature is built based on the robust cold-adapted oxidase-like activity of ε-MnO2. These results not only provide new insights for the rational design of cold-adapted nanozymes but also broaden the application of nanozymes in low-temperature industrial processes.

The Engineering Screen of Photoactive Nanozymes Based on N-Containing Covalent Organic Frameworks for Antibacterial Application.

Covalent organic frameworks (COFs) are a class of highly efficient photocatalytic organic semiconductor materials, which have been developed for the design of photoactive nanozymes. Nitrogen (N)-heterocycles could effectively improve their photocatalytic activity of COFs. However, the systematic exploration of photoactive nanozymes based on N-containing COFs is still lacking. In this work, a series of N-containing Schiff-base linkages of COFs are designed and synthesized to explore high-performance photoactive nanozymes. In addition, Fe ions are introduced through post-modification of COFs, which can not only effectively extend the band-edge absorption of COFs to the red-light region and thereby broaden its biological applications, but also introduce single site of Fe to enrich the types of free radicals in the catalytic products. The activities of photoactive nanozymes based on N-containing COFs are systematically studied, and their catalytic mechanisms are uncovered. Interestingly, it is not as commonly recognized that the more content of N, the better for photocatalysis or the construction of photoactive nanozyme. Furthermore, the selected photoactive nanozymes are used for antibacterial applications, which showed good activity against Escherichia coli.

Screening Oxidoreductase Activities of Nanozymes: Toward Activity‐Tailored Guidelines

Nanozymes (NZs) are nanomaterials able to mimic natural enzymes, offering the advantages of better durability, wider range of operational conditions, and easier functionalization. In addition, some NZs exhibit multiple enzyme‐like activities and effective tandem/self‐cascade reactions. In this context, metallic and metal–oxide nanoparticles are among the most promising candidates for biomedical/biotechnological applications, thanks to their efficient oxidoreductase activities. However, characterizing NZs is challenging because the experimental set‐up of different assays strongly influence their performances. Consequently, currently available literature provides limited understanding of the characteristics of the various NZs, especially in terms of activity‐related performance, hindering their optimal selection and applicative potential. Here, leveraging on accurate characterization methodology, we report a direct comparison of several NZs (gold‐Au, platinum‐Pt, palladium‐Pd, ceria, iron oxide) possessing multi‐enzymatic activities. Our main findings indicate that 1) PtNZs outperform the other tested NZs in catalase‐like activity; 2) Pt and PdNZs present superior superoxide dismutase‐like activity; 3) for peroxidase‐ and oxidase‐like activity, the best‐performing NZ is substrate‐dependent; 4) competitive reactions in multifunctional NZs play a key role in their specific performance, and AuNZs can be the optimal choice in some peroxidase/oxidase configurations; 5) metallic NZs are more efficient than metal‐oxide ones, but 6) ceria presents unique phosphatase‐like activity.

Graphyne-supported manganese single-atom nanozyme sensor array for bisphenol identification

Bisphenols, as common industrial raw materials, are widely used in food packaging such as plastics. However, their migration and residue may affect the hormone secretion of the human body and then lead to health problems. Therefore, a low-cost, rapid and simple detection method that can simultaneously detect multiple bisphenols is very necessary. In this work, two types of manganese single-atom nanozymes with excellent peroxidase-like activity were synthesized with graphyne as a support. A high-throughput colorimetric sensor array was constructed using three types of nanozymes (Mn-GY, Mn-GY-2N, GY-2N) to distinguish various bisphenols. Due to the absorption of bisphenol molecules on the surface of nanozymes, the activity of nanozymes decreases differently, when different bisphenols are added to the catalytic system. The results proved that the prepared sensor had good linear relationships at both low and high concentrations for determination of five bisphenols. The LODs of BPA, BPS, BPF, BPAF, and Diphenolic Acid were 0.443, 0.280, 0.277, 0.424, and 0.326 μM respectively. Compared with traditional sensors, the sensor array can simultaneously detect multiple analytes with high throughput, showing great advantage in dealing with complex samples. Combined with machine learning algorithms, five bisphenols can be successfully identified by the obtained array data. The sensor array also demonstrated excellent performance in the detection of both mixed samples and real samples. This high-throughput colorimetric sensor array achieves accurate and sensitive detection of bisphenol substances, providing new means and ideas for enhancing food safety. At the same time, the simple and rapid identification of structurally similar compounds demonstrates its potential for more precise analysis, providing possibilities for future development.

Rational synthesis of FeWO4 nanozyme with sonopiezoelectric and co-catalytic activity for colorimetric detection of deferiprone

Colorimetric sensing based on nanozyme has been extensively applied in the field of biosensing. The analysis time and detection sensitivity depend on the activity of nanozyme. At present, the methods of traditional regulating the activity of nanozyme mainly include internal and external regulation. However, it is still a challenge for internal and external stimuli to coordinate the regulation of nanozyme activity. Both piezoelectricity and co-catalysis can expedite the rate limiting step (Fe3+/Fe2+cycle) of the Fenton reaction hence facilitating the peroxidase-like (POD-like) activity of nanozyme. In this study, we synthesized FeWO4 nanorod that possess sonopiezoelectric and co-catalytic properties. The Fe3+/Fe2+ cycle of FeWO4 nanorods can be boosted by the internal Fe, W co-catalytic reaction and the external ultrasound stimuli generated e−. Deferiprone (DFP), a small molecule of iron chelating agent, is used clinically to chelate excess iron in thalassemia patients. It can specifically inhibit the POD-like activity of the iron-based nanozyme due to coordination with Fe. Based on the above principles, we constructed a colorimetric sensing platform based on FeWO4 nanozyme for colorimetric detection of DFP in urine of thalassemia patients. The linear range, limit of detection and recovery of the developed colorimetric sensing method based on FeWO4 nanozyme platform are 0.1–5 μM, 0.05 μM and 97.4 % − 105.4 %, respectively. This work not only promotes the development of the method to regulate the activity of nanozyme, but also provides a simple method for the monitoring of DFP.

Blue-LED assisted Photodegradation kinetics of rhodamine-6G dye, enhanced anticancer activity and cleavage of plasmids using Au-ZnO nanocomposite.

The plasmonic metal doping on the UV-active metal oxide nanoparticle turns the resultant plasmonic metal-metal oxide (PMMO) into visible light active and upon exogenous illumination the photogenerated energetic charge carriers and the in situ generated reactive oxygen species (ROS, e.g. ·OH and O2 -·) authoritatively enhances its biological and catalytic activity. Herein, a hexagonal rod-shaped ZnO nanoparticles (NP) precursor was prepared using the sol-gel method, which in the presence of varying concentrations of gold (0.005M, 0.01M, and 0.015M) via a greener citrate reduction method afforded a nanocrystalline Au-ZnO nanocomposite. Using which, the visible-light driven photo-degradation kinetics investigation of rhodamine-6G (R6G) dye under blue LED irradiation were carried out. The use of 20mg 0.015-Au-ZnO completes the degradation of R6G (97.0%, k=6.5 X 10-3s-1at pH 7) within 55min while 50mg of 0.015-Au-ZnO catalyst improves the rate of R6G degradation (15min 97.8%, k=14.8×10-3 s-1) and it is reusable up to three cycles. The LC-MS spectra of the remains of R6G (after 15min) identified various low molecular ions (up m/z=65). Further, the blue-LED assisted anti-cancer studies (MTT assay) using 0.015-Au-ZnO towards human lung cancer cells (A549), breast cancer cells (SKBr3) show high anti-proliferation rate and low cytotoxicity against healthy human embryonic kidney cells (HEK-293) with an IC50 value of 65, 53 and 124μg/mL respectively. Also, the AO-EB dual staining and DCFH-DA analysis of SKBr3 and A549cells revealed ROS-mediated cell death via apoptosis. Moreover, plasmid cleavage studies against supercoiled pBR322 DNA result in single-stranded linear DNA without traversing the nicked circular form, suggesting the possible DNA targeting activity of Au-ZnO nanozyme. Thus, the synthesized Au-ZnO nanocomposite shows excellent photocatalytic and biological activity.

Rationalizing hydrogel-integrated peroxidase-mimicking nanozymes for combating drug-resistant bacteria and colorimetric sensing.

Due to the easy preparation, high stability and environmental friendliness, nanozymes are frequently used as promising substitutes to natural enzymes. However, the efficacy of nanozymes in biomedicine aspects is often hampered by their potential biotoxicity and limited bioavailability, which prompted structure adaption or carrier design to maximize nanozymes performance. Despite considerable efforts on carriers to deliver nanozymes efficiently, the systematic studies on enzyme-like activities of nanozymes related to platforms of nanozyme@carrier are sparse. Here, five types of hydrogel carriers composed by sodium alginate (SA), chitosan, gelatin, gelatin methacryloyl (GelMA), and polyacrylamide (PAM) were formed by distinct mode of polymerization to optimize the suitable carrier for peroxidase (POD)-mimic nanozyme consisted of hemin and bovine serum albumin (BSA). Among these proposed carriers, SA hydrogel emerged as the most effective carrier due to its compatible crosslinking mechanism and desirable stability for nanozyme functioning. By incorporating the POD-mimic nanozyme into the SA hydrogel, the catalytic performance of the nanozyme was effectively preserved, leading to improved antibacterial effects and superior sensing ability towards the colorimetric measurement of H2O2. Based on the rationalization of hydrogel carriers, the proposed study not only helped to understand the structure-function relationship between nanozyme and carriers, but provided an integrated nanoplatform of POD-mimic nanozyme with environmental disinfection as well as biomedical applications.

Tailored Metal–Organic Framework‐Based Nanozymes for Enhanced Enzyme‐Like Catalysis

AbstractThe global crisis of bacterial infections is exacerbated by the escalating threat of microbial antibiotic resistance. Nanozymes promise to provide ingenious solutions. Here, we reported a homogeneous catalytic structure of Pt nanoclusters with finely tuned metal–organic framework (ZIF‐8) channel structures for the treatment of infected wounds. Catalytic site normalization showed that the active site of the Pt aggregates structure with fine‐tuned pore modifications structure had a catalytic capacity of 14.903×105 min−1, which was 18.7 times higher than that of the Pt particles in monodisperse state in ZIF‐8 (0.793×105 min−1). In situ tests revealed that the change from homocleavage to heterocleavage of hydrogen peroxide at the interface of the nanozyme was one of the key reasons for the improvement of nanozyme activity. Density‐functional theory and kinetic simulations of the reaction interface jointly determine the role of the catalytic center and the substrate channel together. Metabolomics analysis showed that the developed nanozyme, working in conjunction with reactive oxygen species, could effectively block energy metabolic pathways within bacteria, leading to spontaneous apoptosis and bacterial rupture. This pioneering study elucidates new ideas for the regulation of artificial enzyme activity and provides new perspectives for the development of efficient antibiotic substitutes.

Tailored Metal-Organic Framework-Based Nanozymes for Enhanced Enzyme-Like Catalysis.

The global crisis of bacterial infections is exacerbated by the escalating threat of microbial antibiotic resistance. Nanozymes promise to provide ingenious solutions. Here, we reported a homogeneous catalytic structure of Pt nanoclusters with finely tuned metal-organic framework (ZIF-8) channel structures for the treatment of infected wounds. Catalytic site normalization showed that the active site of the Pt aggregates structure with fine-tuned pore modifications structure had a catalytic capacity of 14.903×105 min-1, which was 18.7 times higher than that of the Pt particles in monodisperse state in ZIF-8 (0.793×105 min-1). In situ tests revealed that the change from homocleavage to heterocleavage of hydrogen peroxide at the interface of the nanozyme was one of the key reasons for the improvement of nanozyme activity. Density-functional theory and kinetic simulations of the reaction interface jointly determine the role of the catalytic center and the substrate channel together. Metabolomics analysis showed that the developed nanozyme, working in conjunction with reactive oxygen species, could effectively block energy metabolic pathways within bacteria, leading to spontaneous apoptosis and bacterial rupture. This pioneering study elucidates new ideas for the regulation of artificial enzyme activity and provides new perspectives for the development of efficient antibiotic substitutes.

Nanozymes as Antibacterial Agents: New Concerns in Design and Enhancement Strategies.

Nanozymes exhibiting natural enzyme-mimicking catalytic activities as antibacterial agents present several advantages, including high stability, low cost, broad-spectrum antibacterial activity, ease of preparation and storage, and minimal bacterial resistance. Consequently, they have attracted significant attention in recent years. However, the rapid expansion of antimicrobial nanozyme research has resulted in pioneering reviews that do not comprehensively address emerging concerns and enhancement strategies within this field. This paper first summarizes the factors influencing the intrinsic activity of nanozymes; subsequently, we outline new research considerations for designing antibacterial nanozymes with enhanced functionality and biosafety features such as degradable, imageable, targeted, and bacterial-binding nanozymes as well as those capable of selectively targeting pathogenic bacteria while sparing normal cells and probiotics. Furthermore, we review novel enhancement strategies involving external physical stimuli (light or ultrasound), the introduction of extrinsic small molecules, and self-supplying H2O2 to enhance the activity of antibacterial nanozymes under physiological conditions characterized by low concentrations of H2O2 and O2. Additionally, we present non-redox nanozymes that operate independently of highly toxic reactive oxygen species (ROS) alongside those designed to combat less common pathogenic bacteria. Finally, we discuss current issues, challenges faced in the field, and future prospects for antibacterial nanozymes.